# Video tachometer vs Duct Sensor Assistant

The clearest difference is in-app purchases: Duct Sensor Assistant at none against Video tachometer's 1. Duct Sensor Assistant also leads on iOS requirement (12.0 vs 15.6). On price, update cadence, ads and device support there is nothing between them.

Both are free to download. Video tachometer sells 1 one-off in-app purchase. Duct Sensor Assistant asks for nothing beyond the download.

Video tachometer ships an update every 3 months, Duct Sensor Assistant every 6 months. The most recent releases landed on September 21, 2026 and September 16, 2026 respectively.

## The numbers

| Metric | Video tachometer | Duct Sensor Assistant |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.6 (84 ratings)](https://appshunter.io/ios/app/video-tachometer/id1492583587/reviews)** | — |
| Number of ratings | **84** | — |
| Positive reviews | 84.6% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | **Every 3 months** | Every 6 months |
| Monetization | Free with in-app purchases | — |
| Size | 5 MB | 31 MB |
| Requires iOS | 15.6 | **12.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Dmitriy Kharutskiy](https://appshunter.io/developer/817385891) | [BELIMO Automation AG](https://appshunter.io/developer/1149281298) |

## What reviewers say

### Video tachometer

[App page](https://appshunter.io/ios/app/video-tachometer/id1492583587)

This app uses slow-motion video to create a strobe light effect, allowing you to measure rotational speeds. It records video with detailed information like frame rate and exposure, and offers customizable text overlays.

**Highlights:** Strobe light effect simulation, Rotational speed measurement (RPM/Hz), Slow-motion video recording, Customizable text overlays on video, Adjustable frame rate and exposure, Records 4K video (if supported)

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Full version | $2.99 | one-time |

**What reviewers like**

- 👍 Easy to use
- 💡 Clever approach
- 🚀 Works beautifully
- 👍 Very handy
- 👍 Accurate measurements

**What reviewers complain about**

- 💸 Too much in paid version
- 💰 Free version limited
- 🤔 Confusing settings initially
- 👎 Unclear about recording
- 👎 No built-in video recording

**Reported bugs**

- Does not read anything
- Pop-ups for paid features
- Interface visible in screen recording

**Requested features**

- Ability to record video
- Slow phase shift mode
- Improved UI for initial setup
- Long press for gradual increment/decrement


### Duct Sensor Assistant

[App page](https://appshunter.io/ios/app/duct-sensor-assistant/id1559862597)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Video tachometer free?

Video tachometer is free to download, with in-app purchases available.

### Is Duct Sensor Assistant free?

Duct Sensor Assistant is free to download, with no in-app purchases.

### Do Video tachometer or Duct Sensor Assistant have ads?

Neither Video tachometer nor Duct Sensor Assistant shows ads.

### Which is updated more often, Video tachometer or Duct Sensor Assistant?

Video tachometer ships an update every 3 months, and Duct Sensor Assistant every 6 months. Most recently, Video tachometer was updated on September 21, 2026 and Duct Sensor Assistant on September 16, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*